The present invention relates to the application of repositionable pressure-sensitive adhesive sheets to articles such as advertising media, newspapers, envelopes or the like and the resultant stacked assemblies of such materials.
Repositionable note sheets, such as the Post-it.RTM. brand notes sold by Minnesota Mining and Manufacturing Company of St. Paul, Minn., are quite common and in every day use. Such note sheets in familiar form are available in stacks or pads of sheets, one adhered to another. A repositionable note sheet has a first side which is partially coated with a repositionable pressure-sensitive adhesive (RPSA) and a second side which is either plain (no printing) for writing a note, or which may have a preprinted message or design thereon. Such a repositionable note sheet is useful for calling attention to a particular section of a document, for marking a page in a document or book, or for leaving a removable and repositionable note that can be adhered to just about any clean surface.
Advertising materials using repositionable note sheets on print media have been produced in the fields of direct-mail advertising, newspapers, magazines, advertising signatures, and the like. The note sheets are repositionable so that they can be removed from those advertising materials and adhered at another location (for example, a desk or refrigerator) to remind the reader to call the advertiser or to use the note sheet as a coupon at a later date.
Advertising articles bearing note sheets are typically produced by sequentially applying the note sheets in the same location on a series of printed advertising pieces. For example, newspapers and magazines have been printed and assembled in their entirety, or in sections thereof (e.g., advertising signatures), and then note sheets have been sequentially applied to the same location on a particular page of the newspaper or magazine. Direct mail advertising materials have also been produced which include a repositionable pressure-sensitive note sheet. Typically, such direct-mail advertising pieces are produced using a web of paper on which is printed multiple repeating direct-mail messages, and a note sheet is sequentially attached in generally the same location on each of those repeating messages on that web. The web is then cut into discrete direct-mail piece materials for further processing.
RPSA note sheets have been previously applied by hand to advertising materials and newspapers. Apparatus for automated application of RPSA note sheets to certain articles have been developed by Minnesota Mining and Manufacturing Company, and are disclosed in co-pending U.S. patent applications Ser. No. 08/095,722, now abandoned and Ser. No. 08/729,780, both commonly owned by the assignee of the instant application, Minnesota Mining and Manufacturing Company, and incorporated herein by reference.
Another common method to advertise in the newspaper industry is to apply a small pressure-sensitive adhesive (PSA) label on the masthead of the newspaper. The newspaper USA Today pioneered this approach. For example, a small PSA label (approximately 0.5 inch (1.25 cm) high and about 1 inch (2.5 cm) across) may be applied to promote the name of a hotel providing a complimentary USA Today newspaper to its overnight guests. It has been reported that these PSA labels have been applied to newspapers at speeds of 45,000 units per hour, as applied along the shorter dimension of the label in the machine direction. This approach has proved to be an effective advertising technique, but has the disadvantage that the labels (bearing a non-repositionable or permanent PSA) destroy the underlying print of the newspaper and cannot be repositioned or removed. Newspaper space is premium advertising space, particularly when the space is on the top half of the front page of a newspaper. This is because newspapers are typically distributed in a folded configuration, with the top half of the front page of the newspaper being the first portion of the newspaper which the reader or potential purchaser sees. The use of a PSA label having a permanent adhesive eliminates the possibility of the area under the label being used for effective advertising, since it is completely and permanently covered. Hence, an advantage to using repositionable pressure-sensitive adhesive note sheets on newspapers for advertising purposes is that the note sheet may be removed, thereby allowing the reader to be exposed to the information thereunder.
In addition to the fact that the PSA label permanently defaces the front of the newspaper and cannot be removed easily, the use of a label has other drawbacks. Since the labels are applied sequentially and in the same location on the top half of the front page of a folded newspaper, the same information is always covered on every newspaper. As mentioned, the value of newspaper space is quite high, and the newspaper must therefor trade the value of having a label versus the value of the printing on the underlying face of the newspaper page. In addition, the sequential PSA label application operation limits the machine-direction length of the pressure-sensitive adhesive label stock. The application of a label having a larger machine-direction length would slow the production of the newspapers. For example, sequentially applying a label having a three-inch (7.5 cm) machine-direction length would cause the overall production of newspapers to fall by two-thirds in order to allow the labeling operation to keep pace. This slowing of production is an unacceptable consequence of trying to provide a larger PSA label on a newspaper.
Labels are not note sheets. Labels are generally completely covered on one side with pressure-sensitive adhesive and generally are intended to transmit information, not to be removed by the recipient and not to be put to firer use (e.g., as a reminder or coupon). Note sheets, however, are used to draw attention to information, and can be removed and subsequently repositioned many times. Consequently, 3M Post-it.RTM. brand notes are ubiquitous tools in the office, and are now often found sticking around the home as well.
The application of a label or note sheet to the front page of a folded newspaper does not have any appreciable effect on the thickness of the folded newspaper. However, that is not necessarily the case when a note sheet or label is applied to a single page or to an advertising signature comprising just a few pages. When a thin article or single page bearing a note sheet is collated and assembled in stacked form, with the note sheet placed in an identical location on each item, it can make a significant difference in the height of the stack of such assemblies (e.g., even doubling it), depending on the relative thicknesses of the items and note sheets. This is problematic for later processing of such article assemblies, since one portion or corner of the stack may have a significantly greater height than other portions thereof This can cause misfeeds in further printing, collating or folding apparatus for handling the stack of article assemblies.
A method used to provide a pressure-sensitive mailing label attached to a letterhead has been commercialized by Avery Corporation, and is disclosed in U.S. Pat. No. 5,316,344. A stack of bond paper was provided for printing, with each sheet of paper having attached thereto a removable pressure-sensitive adhesive label. Each label throughout the stack was in generally the same location on each sheet of paper. While this is a convenient method to simultaneously print letters and associated labels, it has the disadvantage of causing a portion of the stack to be much higher than the rest of the stack. Because the label has roughly the same thickness as the bond paper, the area carrying the label bulges much higher than the rest of the stack. This can result in misfeeds by common copiers or digital printers, which are otherwise designed to feed from a stack having relatively straight and aligned sides. Finally, because all of the labels are generally vertically aligned throughout the stack, about only half as many sheets may fit into a feeding tray as normal. Frequent stopping of production is then necessary in order to refill the paper trays.
Digital printing and copying devices are becoming more popular to produce varieties of materials, from direct-mail literature to catalogs. By using digital printing and copying devices, the printing on each sheet can take a different form or orientation to achieve customer desires. Consequently, duplex printing, and alternating images to meet the demands of unique media, are well known and supported in the print media industry.